Increasingly aggressive treatment has significantly improve the prognosis for many previously fatal childhood illnesses. However, the intense and often invasive interventions have put these survivors at risk for mental health problems. We proposes to study the applicability of a post- traumatic stress model to these children, beginning with studies of childhood cancer survivors. Our five year plan includes formal coursework, collaborative research, independent research, and curriculum development with the goal of identifying predictors and developing interventions which could prevent later problems in children at medical risk, and their parents. With expert assistance we will develop both theoretical and practical skills in research design and analyses, development and evaluation of research instruments, and intervention strategies. The pilot studies with bone marrow transplant patients have been used as a basis for prospective, longitudinal study of childhood cancer patients. Basic hypotheses of this study include the presence of post-traumatic stress symptoms in childhood cancer patients and their parents, the correlation of these symptoms with the intensity of treatment and perceived life threat, and decreased function in school and perceived self-competence. Approximately 160 children aged 8 to 18 who are receiving treatment for cancer at UCLA will be entered over a period of 5 years. Each child and a parent will be interviewed within one month of beginning treatment. Follow-up-self-report questionnaires will then be mailed 6, 12, and 34 months later. Control subjects will be recruited from local schools, and group matched by age, gender, ethnicity and socioeconomic status. This study will serve as the basis for identifica- tion of predictors of high risk children and parents, and development of appropriate interventions. Generalization of the study results to other populations of children at medical risk will be tested in subsequent studies.